doi: 10.3174/ajnr.A1500
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American Journal of Neuroradiology 30:1459-1468, September 2009
© 2009 American Society of Neuroradiology
REVIEW ARTICLES
Dangerous Extracranial–Intracranial Anastomoses and Supply to the Cranial Nerves: Vessels the Neurointerventionalist Needs to Know
aFrom the Department of Radiology (S.G., S.P.), Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
bDepartment of Diagnostic Imaging (S.G., D.A.), Hospital for Sick Children, Toronto, Canada
cDivision of Neuroradiology (T.K.), Department of Medical Imaging, University of Toronto, Toronto Western Hospital, Toronto, Ontario, Canada.
Please address correspondence to T. Krings, MD, PhD, University of Toronto, Toronto Western Hospital, UHN, Division of Neuroradiology, 399 Bathurst St, 3MCL-429, Toronto, ON, M5T 2S8, Canada; e-mail: timo.krings{at}uhn.on.ca
SUMMARY: Transarterial embolization in the external carotid artery (ECA) territory has a major role in the endovascular management of epistaxis, skull base tumors, and dural arteriovenous fistulas. Knowledge of the potential anastomotic routes, identification of the cranial nerve supply from the ECA, and the proper choice of embolic material are crucial to help the interventionalist avoid neurologic complications during the procedure. Three regions along the skull base constitute potential anastomotic routes between the extracranial and intracranial arteries: the orbital, the petrocavernous, and the upper cervical regions. Branches of the internal maxillary artery have anastomoses with the ophthalmic artery and petrocavernous internal carotid artery (ICA), whereas the branches of the ascending pharyngeal artery are connected to the petrocavernous ICA. Branches of both the ascending pharyngeal artery and the occipital artery have anastomoses with the vertebral artery. To avoid cranial nerve palsy, one must have knowledge of the supply to the lower cranial nerves: The petrous branch of the middle meningeal artery and the stylomastoid branch of the posterior auricular artery form the facial arcade as the major supply to the facial nerve, and the neuromeningeal trunk of the ascending pharyngeal artery supplies the lower cranial nerves (CN IX–XII).